Abstract: A protected electrical power system may comprise a feeder between a power source and an electrical load. A first current transformer may be positioned on the feeder in a first location. The first current transformer may have a shunt resistor electrically connected across its winding. A second current transformer may be positioned at a second location on the feeder. A control unit may be interposed between the first and second current transformers and may be interconnected with the first and second current transformers on current-monitoring loops independent from the feeder. The control unit may be responsive to a predetermined differential in feeder (DF) current between the first and second current transformers to disconnect the power source from the electrical load. The control unit may have a compensation network for reducing DF error resulting from presence of the shunt resistor in the first current transformer.

Abstract: Pre-charge circuitry allows capacitive loads connected to a solid state power controller to be gradually charged up by a PWM, generated with a cycle by cycle current limit, switching a single MOSFET in series with an inductor, before the SSPC is turned on. The pre-charge circuitry may require only three additional components, e.g., a MOSFET, an inductor and a diode, along with a designated MOSFET gate driver.

Abstract: A solid state power controller (SSPC) often contains electronic circuitry which could be damaged or upset by the excessive transient voltages induced by the lightning and SSPC could result in undesirable (or nuisance) trips due to lightning strikes. The present invention is intended to address the “nuisance trip” issue, by relying on the lightning indicative signals to distinguish between the transient current surge due to the lightning strike and that due to the circuit fault in the power distribution channel. The present invention utilizes either the break-down current in a transient voltage suppression (TVS) device, or a voltage signal at the output of the SSPC as the indication of lightning strike, to avoid nuisance trips.

Abstract: High-power power distribution in an aircraft may use solid state power controller (SSPC) technology. A conventional electromechanical contactor may be used, in series, with a solid state switching device (SSSD) to achieve high-power power distribution. Since the electromechanical contactor does not need to be rated for arc handlings during normal SSPC operation, the electromechanical contactor may be simplified, resulting in cost, weight, volume, and failure rate reductions. The power distribution apparatus and methods of the present invention may be applicable for both alternating current (AC) and direct current (DC) applications and can be modified to form a three phase SSPC.

Abstract: An aircraft engine starting system may comprise a starter motor, a start controller for controlling the starter motor to operate with a desired torque output, and a processor for determining torque profiles for the starter motor. The processor may provide an initial torque profile responsively to ambient condition of the engine. The processor may also provide modifications to the initial torque profile responsively to temperature of the start controller.

Abstract: An electrical distribution control system for a vehicle such as an aircraft may be provided fire-suppression protection without requiring that all control elements are located in a fire-containment enclosure. A primary electric load center (ECL) may be located in a fire-containment equipment bay. Secondary power control centers (SPC's) may be located away from the equipment bay and close to set of loads which are controlled by the SPC's. Each SPC may be provided with a fire detecting sensor that may signal the ECL to interrupt input power to the SPC in the event of a fire in the SPC. The SPC may be constructed from self-extinguishing material. In an absence of input power to the SPC, a fire may self extinguish, thus preventing flame propagation or production of excessive external heat.

Abstract: A system and method are disclosed for regulating a generator controlled power signal. An exemplary embodiment of the system may include both a digital voltage regulator and an analog voltage regulator and a selector switch configured to switch modulation control between the digital and analog voltage regulators. A watchdog detection circuit may be included for detecting an upsetting event in the digital voltage regulator and may trigger switching of the generator excitation input voltage modulation from the digital voltage regulator to the analog voltage regulator. An exemplary embodiment of the method may include modulating the generator excitation input voltage using the digital voltage regulator, detecting an occurrence of an upsetting event in the digital voltage regulator, disabling the digital voltage regulator, and switching modulation of the generator excitation input voltage to the analog voltage regulator.

Abstract: A high voltage direct current (HVDC) power distribution system comprises at least one power bus; at least one load conductor; and a hybrid contactor for interconnecting the at least one power bus and the at least one load conductor and through which inductive energy passes upon disconnection of the at least one load conductor from the at least one power bus. A first portion of the inductive energy passes through the hybrid contactor as an arc. A second portion of the inductive energy passes through the hybrid contactor as resistively dissipated heat.

Abstract: An electrical power distribution system for a vehicle may provide from alternate sources of power to an electrical load. Two solid state power contactors (SSPC's) may provide connectivity paths between two power sources and the equipment. The SSPC's may be interconnected so that power to the load is provided on a first connectivity path between a first source of power and the load, unless and until a power interruption occurs on the first path. In the event of power interruption, the SSPC's actuate a second connectivity path between a second source of power and the load. Transfer of power sources may occur in a time period that is less than an equipment transparency time of the load.

Abstract: A solid state power controller (SSPC) often contains electronic circuitry which could be damaged or upset by the excessive transient voltages induced by the lightning and SSPC could result in undesirable (or nuisance) trips due to lightning strikes. The present invention is intended to address the “nuisance trip” issue, by relying on the lightning indicative signals to distinguish between the transient current surge due to the lightning strike and that due to the circuit fault in the power distribution channel. The present invention utilizes either the break-down current in a transient voltage suppression (TVS) device, or a voltage signal at the output of the SSPC as the indication of lightning strike, to avoid nuisance trips.

Abstract: A solid state switching device (SSSD) for AC and DC high power solid state power controller includes, for DC applications, a MOSFET and an IGBT connected in parallel and an optional zener diode connecting a collector and a gate of the IGBT. For AC applications, the SSSD includes a “back to back” pair of MOSFETs connected in parallel with a pair of counter-parallel IGBTs, each in series with a diode, and, optionally, zener diodes “back to back” with conventional diodes connecting a collector and a gate of each of the IGBT. A method of switching establishes a sequence of turning on/off the MOSFET(s) and the IGBT(s) wherein the IGBT(s) turn on before and turn off after the MOSFET(s). A negative feedback prevents a voltage of SSSD rising above predetermined level.

Abstract: An electrical distribution control system for a vehicle such as an aircraft may be provided fire-suppression protection without requiring that all control elements are located in a fire-containment enclosure. A primary electric load center (ECL) may be located in a fire-containment equipment bay. Secondary power control centers (SPC's) may be located away from the equipment bay and close to set of loads which are controlled by the SPC's. Each SPC may be provided with a fire detecting sensor that may signal the ECL to interrupt input power to the SPC in the event of a fire in the SPC. The SPC may be constructed from self-extinguishing material. In an absence of input power to the SPC, a fire may self extinguish, thus preventing flame propagation or production of excessive external heat.

Abstract: A method of managing a plurality of subscribers using a communication network involving: obtaining network usage data for a plurality of service flows associated with the plurality of subscribers using the network; from the network usage data, determining which of the plurality of subscribers has been using an excess amount of bandwidth; determining that at least some part of the network is currently in a congested state; and in response to determining that at least some part of the network is currently in the congested state, sending a policy decision to a gateway device that controls bandwidth resources currently being provided to the identified subscriber, said policy decision instructing the gateway device to reduce network bandwidth that is currently being provided to support existing service flows for the identified subscriber.

Abstract: A solid state switching device (SSSD) for AC and DC high power solid state power controller includes, for DC applications, a MOSFET and an IGBT connected in parallel and an optional zener diode connecting a collector and a gate of the IGBT. For AC applications, the SSSD includes a “back to back” pair of MOSFETs connected in parallel with a pair of counter-parallel IGBTs, each in series with a diode, and, optionally, zener diodes “back to back” with conventional diodes connecting a collector and a gate of each of the IGBT. A method of switching establishes a sequence of turning on/off the MOSFET(s) and the IGBT(s) wherein the IGBT(s) turn on before and turn off after the MOSFET(s). A negative feedback prevents a voltage of SSSD rising above predetermined level.

Abstract: A method of creating a network-initiated secondary packet data service instance includes sending a content request for application data from a mobile station to an application function through an access network. The method further includes sending a request for a secondary packet data service instance from the application function to a policy function, and evaluating the request for a secondary packet data service instance and determining one or more operational attributes from the evaluation. The method also includes creating the secondary packet data service instance between the application function to the mobile station by arranging one or more network components as a function of the one or more operational attributes. The method further includes transmitting the application data from the application function to the mobile station via the secondary packet data service instance.